From nobody Mon Feb 9 17:25:11 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1562942095; cv=none; d=zoho.com; s=zohoarc; b=Fr6wwq89WNaH+0QjKhlt/zGTP1KXCCN1jJSsYSYDN1pqo12qK37oIIaV6Nzd6f2HPVKlqgWnzCZp8fue+SxWRJflHL8PKuR1OkGsI7gY+ktodtfdWDLwCR43fzA4LbYVqWDpZlG4yfo5pzO3dAE4on4xX7SKlNho/6BTFWbVXUc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1562942095; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=Bs0ktkj/1ECZwNWyes9bAno5QqWlma/zQZOOAUeMWFg=; b=VJf22xgQ9fSWQvAe0P+5ufyK3kzC64fFsVpltqvzrMlEKb3fWZyF5SuF1JjrsKTBkh3JM+D+ZCJI6sv8EmcpzTd4mmsmCq6BrbF6b5j3gmCW46hCrH7Mk3UZWiTaqMhy4OtKXnZhIXW8X1+OJ1oqaE2lcQNubpbTalHt6/p+wtY= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1562942095071941.8560577233585; Fri, 12 Jul 2019 07:34:55 -0700 (PDT) Received: from localhost ([::1]:50046 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlwdP-0004cK-S8 for importer@patchew.org; Fri, 12 Jul 2019 10:34:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45143) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlwbf-0006V6-0W for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:33:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hlwbd-00023C-JX for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:33:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57624) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hlwbd-00022s-AH for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:33:01 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 672F34E908; Fri, 12 Jul 2019 14:33:00 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.118.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E7EA608C2; Fri, 12 Jul 2019 14:32:57 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Fri, 12 Jul 2019 16:32:07 +0200 Message-Id: <20190712143207.4214-20-quintela@redhat.com> In-Reply-To: <20190712143207.4214-1-quintela@redhat.com> References: <20190712143207.4214-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 12 Jul 2019 14:33:00 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 19/19] migration: allow private destination ram with x-ignore-shared X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Thomas Huth , kvm@vger.kernel.org, Juan Quintela , "Dr. David Alan Gilbert" , Yury Kotov , Xu Wang , Jiangshan Lai , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Peng Tao By removing the share ram check, qemu is able to migrate to private destination ram when x-ignore-shared capability is on. Then we can create multiple destination VMs based on the same source VM. This changes the x-ignore-shared migration capability to work similar to Lai's original bypass-shared-memory work(https://lists.gnu.org/archive/html/qemu-devel/2018-04/msg00003.html) which enables kata containers (https://katacontainers.io) to implement the VM templating feature. An example usage in kata containers(https://katacontainers.io): 1. Start the source VM: qemu-system-x86 -m 2G \ -object memory-backend-file,id=3Dmem0,size=3D2G,share=3Don,mem-path=3D= /tmpfs/template-memory \ -numa node,memdev=3Dmem0 2. Stop the template VM, set migration x-ignore-shared capability, migrate "exec:cat>/tmpfs/state", quit it 3. Start target VM: qemu-system-x86 -m 2G \ -object memory-backend-file,id=3Dmem0,size=3D2G,share=3Doff,mem-path= =3D/tmpfs/template-memory \ -numa node,memdev=3Dmem0 \ -incoming defer 4. connect to target VM qmp, set migration x-ignore-shared capability, migrate_incoming "exec:cat /tmpfs/state" 5. create more target VMs repeating 3 and 4 Cc: Dr. David Alan Gilbert Cc: Yury Kotov Cc: Jiangshan Lai Cc: Xu Wang Signed-off-by: Peng Tao Reviewed-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert Message-Id: <1560494113-1141-1-git-send-email-tao.peng@linux.alibaba.com> Signed-off-by: Juan Quintela --- migration/ram.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 8a6ad61d3d..8622b4dc49 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3426,7 +3426,6 @@ static int ram_save_setup(QEMUFile *f, void *opaque) } if (migrate_ignore_shared()) { qemu_put_be64(f, block->mr->addr); - qemu_put_byte(f, ramblock_is_ignored(block) ? 1 : 0); } } =20 @@ -4393,12 +4392,6 @@ static int ram_load(QEMUFile *f, void *opaque, int v= ersion_id) } if (migrate_ignore_shared()) { hwaddr addr =3D qemu_get_be64(f); - bool ignored =3D qemu_get_byte(f); - if (ignored !=3D ramblock_is_ignored(block)) { - error_report("RAM block %s should %s be migrat= ed", - id, ignored ? "" : "not"); - ret =3D -EINVAL; - } if (ramblock_is_ignored(block) && block->mr->addr !=3D addr) { error_report("Mismatched GPAs for block %s " --=20 2.21.0